base64: move it to private for websockets

There are no other consumers for this, and reasonably unlikely to
be others for now.  (Other use cases are JWTs, but that would be
another whole set of functionality that we're not ready to take on.)

5 files changed, 298 insertions, 3 deletions

diff --git a/src/supplemental/websocket/CMakeLists.txt b/src/supplemental/websocket/CMakeLists.txt
index 5d2f4b0c..37273c27 100644
--- a/src/supplemental/websocket/CMakeLists.txt
+++ b/src/supplemental/websocket/CMakeLists.txt
@@ -9,8 +9,9 @@
 #
 
 if (NNG_SUPP_WEBSOCKET)
-    nng_sources(sha1.c sha1.h websocket.c websocket.h)
+    nng_sources(base64.c base64.h sha1.c sha1.h websocket.c websocket.h)
     nng_test(sha1_test)
+    nng_test(base64_test)
 else ()
     nng_sources(stub.c)
 endif ()
diff --git a/src/supplemental/websocket/base64.c b/src/supplemental/websocket/base64.c
new file mode 100644
index 00000000..3c19ad8a
--- /dev/null
+++ b/src/supplemental/websocket/base64.c
@@ -0,0 +1,145 @@
+//
+// Copyright (c) 2014 Wirebird Labs LLC.  All rights reserved.
+// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom
+// the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+#include "base64.h"
+
+#include <ctype.h>
+
+size_t
+nni_base64_decode(const char *in, size_t in_len, uint8_t *out, size_t out_len)
+{
+	unsigned ii;
+	unsigned rem;
+	uint32_t v;
+	uint8_t  ch;
+	size_t   io;
+
+	// Unrolled lookup of ASCII code points.
+	// 0xFF represents a non-base64 valid character.
+	const uint8_t decode[256] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xFF, 0xFF,
+		0x3F, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C,
+		0x3D, 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xFF, 0xFF, 0x00, 0x01,
+		0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B,
+		0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
+		0x16, 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23,
+		0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D,
+		0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
+
+	for (io = 0, ii = 0, v = 0, rem = 0; ii < in_len; ii++) {
+		if (isspace(in[ii])) {
+			continue;
+		}
+
+		if (in[ii] == '=') {
+			break;
+		}
+
+		ch = decode[(int) (in[ii])];
+
+		// Discard invalid characters as per RFC 2045.
+		if (ch == 0xFF) {
+			break;
+		}
+
+		v = (v << 6u) | ch;
+		rem += 6;
+
+		if (rem >= 8) {
+			rem -= 8;
+			if (io >= out_len)
+				return (-1);
+			out[io++] = (v >> rem) & 255u;
+		}
+	}
+	if (rem >= 8) {
+		rem -= 8;
+		if (io >= out_len)
+			return (-1);
+		out[io++] = (v >> rem) & 255u;
+	}
+	return (io);
+}
+
+size_t
+nni_base64_encode(const uint8_t *in, size_t in_len, char *out, size_t out_len)
+{
+	unsigned ii;
+	unsigned rem;
+	uint32_t v;
+	size_t   io;
+
+	const uint8_t encode[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	                           "abcdefghijklmnopqrstuvwxyz"
+	                           "0123456789+/";
+
+	for (io = 0, ii = 0, v = 0, rem = 0; ii < in_len; ii++) {
+		uint8_t ch = in[ii];
+		v          = (v << 8u) | ch;
+		rem += 8;
+		while (rem >= 6) {
+			rem -= 6;
+			if (io >= out_len)
+				return (-1);
+			out[io++] = encode[(v >> rem) & 63u];
+		}
+	}
+
+	if (rem) {
+		v <<= (6 - rem);
+		if (io >= out_len)
+			return (-1);
+		out[io++] = encode[v & 63u];
+	}
+
+	// Pad to a multiple of 3.
+	while (io & 3u) {
+		if (io >= out_len)
+			return (-1);
+		out[io++] = '=';
+	}
+
+	if (io >= out_len)
+		return (-1);
+
+	out[io] = '\0';
+
+	return (io);
+}
diff --git a/src/supplemental/websocket/base64.h b/src/supplemental/websocket/base64.h
new file mode 100644
index 00000000..97ca8968
--- /dev/null
+++ b/src/supplemental/websocket/base64.h
@@ -0,0 +1,42 @@
+//
+// Copyright (c) 2014 Wirebird Labs LLC.  All rights reserved.
+// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom
+// the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+#ifndef NNI_BASE64_INCLUDED
+#define NNI_BASE64_INCLUDED
+
+#include <stddef.h>
+#include <stdint.h>
+
+// Based on base64.c (Public Domain) by Jon Mayo.
+// Base64 is defined in RFC 2045, section 6.8.
+
+// This function encodes an arbitrary byte array into base64
+// null-terminated string.  It returns the number of characters
+// emitted.
+size_t nni_base64_encode(const uint8_t *, size_t, char *, size_t);
+
+// This function decodes a base64 string into supplied buffer.
+// It returns the number of bytes emitted.
+size_t nni_base64_decode(const char *, size_t, uint8_t *, size_t);
+
+#endif
diff --git a/src/supplemental/websocket/base64_test.c b/src/supplemental/websocket/base64_test.c
new file mode 100644
index 00000000..ae8df8e6
--- /dev/null
+++ b/src/supplemental/websocket/base64_test.c
@@ -0,0 +1,108 @@
+//
+// Copyright 2024 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This software is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+#include <string.h>
+
+#include <nng/nng.h>
+
+#include "base64.h"
+
+#include <acutest.h>
+
+typedef struct {
+	char *decoded;
+	char *encoded;
+} test_case;
+
+static test_case cases[] = {
+	{ "", "" },
+	{ "f", "Zg==" },
+	{ "fo", "Zm8=" },
+	{ "foo", "Zm9v" },
+	{ "foob", "Zm9vYg==" },
+	{ "fooba", "Zm9vYmE=" },
+	{ "foobar", "Zm9vYmFy" },
+	{ NULL, NULL },
+};
+
+void
+test_encode(void)
+{
+	int   i;
+	void *dec;
+
+	for (i = 0; (dec = cases[i].decoded) != NULL; i++) {
+		char buf[1024];
+		char name[8];
+		int  rv;
+
+		(void) snprintf(name, sizeof(name), "%d", i);
+		TEST_CASE(name);
+		rv = (int) nni_base64_encode(dec, strlen(dec), buf, 1024);
+		TEST_CHECK(rv >= 0);
+		TEST_CHECK(rv == (int) strlen(cases[i].encoded));
+		buf[rv] = 0;
+		TEST_CHECK(strcmp(buf, cases[i].encoded) == 0);
+	}
+}
+
+void
+test_decode(void)
+{
+	int   i;
+	void *enc;
+
+	for (i = 0; (enc = cases[i].encoded) != NULL; i++) {
+		char   buf[1024];
+		char   name[8];
+		size_t sz;
+
+		(void) snprintf(name, sizeof(name), "%d", i);
+		TEST_CASE(name);
+
+		sz = nni_base64_decode(enc, strlen(enc), (void *) buf, 1024);
+		TEST_CHECK(sz != (size_t) -1);
+		TEST_CHECK(sz == strlen(cases[i].decoded));
+		buf[sz] = 0;
+		TEST_CHECK(strcmp(buf, cases[i].decoded) == 0);
+	}
+}
+
+void
+test_overflow(void)
+{
+	char tmp[1024];
+	for (int i = 1; cases[i].decoded != NULL; i++) {
+		void *enc = cases[i].encoded;
+		void *dec = cases[i].decoded;
+		void *buf = tmp;
+
+		char name[8];
+		(void) snprintf(name, sizeof(name), "%d", i);
+		TEST_CASE(name);
+
+		TEST_CHECK(nni_base64_encode(dec, strlen(dec), buf,
+		               strlen(enc) - 1) == (size_t) -1);
+		TEST_CHECK(nni_base64_encode(dec, strlen(dec), buf, 0) ==
+		    (size_t) -1);
+
+		TEST_CHECK(nni_base64_decode(enc, strlen(enc), buf,
+		               strlen(dec) - 1) == (size_t) -1);
+		TEST_CHECK(nni_base64_encode(enc, strlen(enc), buf, 0) ==
+		    (size_t) -1);
+	}
+}
+
+TEST_LIST = {
+	{ "encode", test_encode },
+	{ "decode", test_decode },
+	{ "overflow", test_overflow },
+	{ NULL, NULL },
+};
diff --git a/src/supplemental/websocket/websocket.c b/src/supplemental/websocket/websocket.c
index 9cb1a677..84d3fd72 100644
--- a/src/supplemental/websocket/websocket.c
+++ b/src/supplemental/websocket/websocket.c
@@ -16,8 +16,7 @@
 #include "core/nng_impl.h"
 #include "supplemental/http/http_api.h"
 
-#include "supplemental/base64/base64.h"
-
+#include "base64.h"
 #include "sha1.h"
 #include "websocket.h"